Three-dimensional finite element analysis of occlusal stress on maxillary first molars with different marginal morphologies restored with occlusal veneers

Three-dimensional finite element analysis of occlusal stress on maxillary first molars with different marginal morphologies restored with occlusal veneers | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Three-dimensional finite element analysis of occlusal stress on maxillary first molars with different marginal morphologies restored with occlusal veneers Qing Chen, Siyang Luo, Yujuan Wang, Zhu Chen, Ying Li, Maohua Meng, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4112384/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 06 Nov, 2024 Read the published version in BMC Oral Health → Version 1 posted 16 You are reading this latest preprint version Abstract Background As a relatively new fixed prosthesis method, there are differences in the research results at home and abroad regarding which edge design of occlusal veneers can achieve the best long-term success rate. Further research is needed. The three-dimensional finite element method was used to conduct stress analysis on occlusal veneers of maxillary first permanent molars with different thicknesses and margin preparation designs. The aim of this study was to provide mechanical research evidence and a reference for exploring standardized clinical protocols for the design of occlusal veneer restorations of maxillary first molars. Method A 3Shape was used to scan the maxillary first molar teeth in vitro, after which 3D printing was performed. Three different edge designs were applied to identical model teeth: straight-beveled finishing line(SFL), chamfer finishing line(CFL), and standard cuspal inclination(SCI). Preparation was carried out with a thickness of 0.5 mm. Using the surface deformation feature, the occlusal veneer was thickened by 0.5 mm and 1.0 mm, and periodontal ligaments were added. They were then placed into the upper and lower jaws and dental arches. Finite element analysis was performed after applying bite force dispersion to the loading area on the mandible following dynamic contact. Results 1. As the thickness increased, the maximum von Mises stress in the occlusal veneer increased for both the SFL and CFL, while the SCI exhibited the opposite trend. 2. The trend of the maximum von Mises stress in the adhesive layer decreases gradually with increasing thickness of the occlusal veneer. The stress of the SFL and CFL is concentrated primarily at the edge position below the functional cusp, resulting in relatively low adhesive stress. However, in the SCI group, the maximum stress at the edge of the adhesive layer exceeded the maximum shear strength of commonly used adhesives. Conclusions Under the experimental conditions, the mechanical properties of the maximum von Mises stress for the SFL, CFL, and SCI Occlusal veneer met clinical needs. Incorporating the minimally invasive concept of tooth preservation, a thickness of 1.0 mm is optimal for glass ceramic occlusal veneers on maxillary first molars. However. occlusal veneer Maxillary first molar Differential edges Three-dimensional finite element Stress Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Highlights This experiment combined finite element analysis with traditional mechanical experiments and prepared models with identical shapes using 3D printing. This approach avoided experimental errors caused by variations in the shape of the natural teeth among individuals, uneven bonding agent thickness, and different design morphologies of the occlusal surface. Additionally, the roughness of the prepared surface more closely resembled the true roughness encountered in clinical settings. By incorporating periodontal ligament hyperelastic materials into jaw dentition, a more realistic nonlinear analysis of periodontal ligament deformation was conducted. By applying biting forces and simulating the movement of biting, dynamic contact results were obtained that differed from the static loading stresses typically used in finite element analyses. Daily chewing is not simply a collision between highly elastic model materials and restorations or teeth, as in extraoral experiments, but rather simulates chewing by using materials that are closer to the mechanical properties of the daily foods of primates. Background In clinical dentistry, various degrees of tooth tissue defects are often caused by decay, attrition, erosion and occult cracks. The incidence of occult cracked teeth is increasing every year. This is one of the reasons for the loss of permanent molars after decay and periodontal disease[ 1 ]. The first molar is the tooth position with the highest incidence of occult cracked teeth[ 2 ]. As a relatively newer form of fixed prosthodontics, occlusal veneer has the distinct advantage of removing fewer tooth structures compared to full-coverage crowns while ensuring effective bonding retention and resistance. It can preserve the maximum amount of healthy tooth tissue. In terms of its load-bearing capacity, a 0.5–1.5 mm occlusal veneer may be an effective alternative to traditional crown restoration under normal anticipated occlusal forces in the mouth[ 3 – 4 ]. The selection of occlusal veneer materials needs to take into account both fracture resistance and bonding performance, so glass-based ceramics[ 5 ] and resin-based ceramics[ 6 ] are commonly used. With the rapid development of chairside CAD/CAM, glass ceramics are becoming increasingly widely used in clinical practice[ 7 ]. Due to the thin material used for occlusal veneer restoration for posterior teeth, which relies entirely on bonding retention, some common clinical complications, including restoration fracture, restoration detachment, and complications affecting periodontal and dental pulp tissue, are common. Currently, clinical reports on occlusal veneer primarily focus on medium-term and short-term observations and case reports, while long-term clinical studies exceeding 10 years are rare. There is significant controversy in both domestic and foreign reports on the thickness of occlusal veneers, with no unanimous consensus. The commonly used preparation methods reported in the literature for clinical applications currently include straight-beveled finishing lines (SFL), chamfer finishing lines (CFL), and standard cuspal inclinations (SCI)[ 8 ]. Among domestic and foreign research results, 分歧 shows that margin design can achieve the best long-term success rate, and further research is needed. This study aimed to explore the optimal design of occlusal veneer margins for maxillary first permanent molars by combining finite element analysis, secondary digital modeling, and traditional mechanical experiments on tooth preparation. By analyzing the stress distribution of different thicknesses and margin preparation shapes under different conditions, this study provides mechanical research evidence and a reference for the exploration and research of the best design plan for occlusal veneer margins of maxillary first permanent molars. Methods A maxillary first molar with an intact crown, no caries damage, and no occult cracks was extracted due to periodontitis. The tooth stones and periodontal tissue were removed with informed consent from the patient. The 3Shape intraoral scanner was used to obtain 3D images. The STL data were exported, and GEOMAGIC 2017 was used to process the polygonization and surface smoothing to obtain a three-dimensional solid model of the maxillary first molar. The three-dimensional solid model was imported into a photopolymerization 3D printer for printing. After trimming the casting channels, 18 maxillary first molar models with morphologies identical to those of the extracted teeth were obtained. Experiment Grouping: According to the different groups, dental preparation was performed based on tooth morphology (Fig. 1 ), and the models were divided into three groups, as shown in Table 1 . Table 1 Experimental groups Edge preparation method occlusal veneer Preparation thickness A straight-beveled finishing line(SFL) 0.5 mm B chamfer finishing line(CFL) 0.5 mm C standard cuspal inclination(SCI) 0.5 mm Using the same experienced surgeon, the same preparation was performed on the different edge morphologies in groups A, B, and C. Grinding and polishing were then applied to round off all points, lines, and angles. Six teeth were prepared for each group. An accuracy of 0.01 mm was used for the thickness measurement scale, and eight fixed measurement points were designed to evaluate the prepared teeth. This was done to ensure that the tooth preparation met the design requirements for each group. Model of maxillary first molar with the same morphology as the isolated tooth. Models prepared for each group After scanning the prepared model after screening with 3Shape, occlusal veneers with different marginal shapes but the same occlusion shape were designed in 3Shape software. Then, the STL files were exported and repaired using Geomagic 2017. After smoothing, polygonization, and surface modeling, the processed three-dimensional solid model of the prepared posterior tooth and the processed three-dimensional solid model of the occlusal veneer were obtained (Fig. 2 ). Three sets of occlusal veneer and prepared tooth STL data were exported to SolidWorks software. The corresponding groups of teeth and occlusal veneers were assembled, and Boolean operations were performed to eliminate scanning errors. Additionally, a 100-micron adhesive layer was created by outwardly expanding the tooth preparation surface contour. Using the surface deformation feature, nine sets of experimental models were created with thicknesses of 0.5 mm and 1.0 mm while maintaining the same occlusal surface morphology (Table 2 ). Additionally, we established periodontal tissue solid models, such as periodontal ligaments, cortical bone, and cancellous bone, through reverse engineering of CBCT data for assembly (Fig. 3 ). Each experimental model was imported into the finite element analysis software Abaqus 2021. Grid division was performed, boundary constraints were set, and material parameters for different structural components were input(Table 3 ). The number of elements and nodes for each model was obtained. 3D solid model of abutment teeth and occlusal veneer after GEOMAGIC 2017 processing. Finite element model Table 2 After the deformation of the surface, the edge preparation methods were divided into 9 experimental groups. groups Edge preparation method occlusal veneer Preparation thickness A A1 straight-beveled finishing line 0.5 mm A2 straight-beveled finishing line 1.0 mm A3 straight-beveled finishing line 1.5 mm B B1 chamfer finishing line 0.5 mm B2 chamfer finishing line 1.0 mm B3 chamfer finishing line 1.5 mm C C1 standard cuspal inclination 0.5 mm C2 standard cuspal inclination 1.0 mm C3 standard cuspal inclination 1.5 mm Table 3 Various material accessories parameters Material attributes modulus of elasticity/MPa Poisson's ratio enamel [ 9 ] 84100 0.30 dentine [ 9 ] 15000 0.31 adhesives[ 10 ] 19000 0.28 Periodontal ligament[ 11 ] 2.7 0.45 Cortical bone[ 11 ] 13700 0.30 Cancellous bone[ 11 ] 345 0.31 Lithium disilicate ceramics 95000 0.19 Bite[ 12 ] 20 0.47 Constraint conditions are added to set the freedom degree of the tooth root section to 0 (i.e., displacements and rotations in the X, Y, and Z directions are all constrained to 0). A simulated maximum biting force of 800 was applied to the mandible, which is the force borne by the teeth.[ 13 ] Results To separate the tooth model from the jawbone model, the obstruction of the jawbone was removed, and the peak stress results of each group and component under the same biting force loading were observed according to three thicknesses (0.5 mm, 1.0 mm, 1.5 mm) and three edge design forms (Table 4 ,Fig. 4 ). For Groups A and B of occlusal veneers, as the thickness of the occlusal veneer increases, the maximum von Mises stress also increases. Group B exhibited relatively smaller changes, but Group C showed the opposite trend. Group C1 had the highest von Mises stress, and as the thickness of the occlusal veneer increased, the stress decreased. For the remaining tooth structure, as the thickness of the occlusal veneer continues to increase, the maximum von Mises stress of the remaining tooth structure gradually increases. The trend of all groups in the adhesive layer was the same, gradually decreasing as the thickness of the occlusal veneer increased. Group C was significantly larger than Groups A and B. The results of finding the peak stress values at the edges of each model part in each group were as follows: The stress was concentrated at the edges of the parts immediately below the palatal cusp, which is the functional cusp, in all groups. The maximum von Mises stress at the occlusal veneer edges was far lower than that at the occlusal contact points. With increasing occlusal veneer thickness, the von Mises stress gradually decreased for all the parts and groups. The stress at the edges of all the components in Group C was significantly greater than that in Groups A and B. The maximum von Mises stress at the occlusal veneer edges was far lower than that at the occlusal contact points. As the thickness of the occlusal veneer increased, the von Mises stress gradually decreased. The maximum von Mises stress at the edges of the adhesive was lower than the most concentrated position of von Mises stress below the occlusal contact points. Compared to those in the adhesive layer, the edges in Group B had relatively lower von Mises stress, while the edges in Groups A and C were close to the maximum von Mises stress of the adhesive layer. As the thickness of the occlusal veneer increased, the von Mises stress gradually decreased (Fig. 5 ). Maximum von Mises stress at the edge of each component in each group. Maximum von Mises stress in different parts of the groups Table 4 Maximum von Mises stresses and stress at the edge for each component in each group. Groups Occlusal veneer Dentin Donding layer Occlusal veneer edges Dental preparation margins Edge of adhesive layer A1 181.12 20.37 14.71 24.52 9.94 14.71 A2 194.13 20.09 13.37 22.12 9.34 13.37 A3 219.62 21.06 12.27 19.18 8.15 11.86 B1 156.89 26.56 11.09 17.22 9.31 9.73 B2 159.93 26.57 10.24 16.84 8.82 8.41 B3 169.58 26.64 9.51 14.52 8.12 7.76 C1 234.12 28.34 28.76 46.03 26.63 25.11 C2 181.53 32.67 27.46 44.69 24.65 24.02 Stress distribution in the occlusal veneer for each group. Stress distribution in the occlusal veneer for each group. Distribution of stresses in the teeth of each group. Stress distribution at the edge of the occlusal veneer in each group. Stress distribution at the edge of the tooth preparation in each group. Adhesive edge stress distribution. Discussion Common complications in occlusal veneer clinical treatment include prosthesis fracture, prosthesis detachment, dentin hypersensitivity and pulp complications, poor marginal sealing, marginal staining and secondary caries. Among them, prosthesis fracture is the primary cause of occlusal veneer failure, which is directly caused by the concentration of occlusal stress[ 14 ]. Cracks often originate from sites where occlusal stress is concentrated at occlusal contact points or at the edges of the prosthesis[ 15 ]. The reason for the detachment of the prosthesis is bonding failure. When the occlusal force is concentrated on the bonding interface for a long time, the bonding material will be fatigued, which will cause the bonding agent to break. However, at present, the mechanical analysis of occlusal veneers mainly relies on traditional methods such as analog impact machines or finite element analysis of static stress loading. Therefore, to avoid complications and prolong the lifespan and survival rate of prostheses, more experimental methods that more closely mimic real preparation and stress conditions are needed. The selection of occlusal materials is not simply a collision between highly elastic model materials and prostheses or teeth, as in extracorporeal experiments, but rather involves various food items with different elastic moduli serving as the medium for force transmission during daily chewing. Reference studies on the mechanical properties of primate foods can provide insights into this process[ 12 ]. A 2 mm-thick plate was placed between the first molars on the right side of the upper jaw. The small plate thickness was selected to ensure optimal adaptation of the deformed plate to the occlusal surface of the molars under biting force. The Young's modulus of the plate was set to 20 MPa, which corresponds to the elastic modulus of the almond under compression, and the Poisson's ratio was 0.47. Such occlusal materials have broader representative significance. In this experiment, the experimental model was assembled into a jawbone model for stress loading, and the finite element analysis results of dynamic contact were obtained. In terms of the final restoration strength, the experimental results of this study confirm the feasibility of minimally invasive treatment with posterior occlusal veneers. Clinically, the normal biting force in the premolar region of the upper jaw is between 222–445 N. During biting, the biting force is approximately 800 N[ 13 ]. The maximum flexural strength of lithium disilicate glass-ceramics reaches 360 MPa[ 16 ]. The average flexural strength values of the occlusal veneer of the maxillary first molars in each group were all lower than the abovementioned values. Dental tissue is a brittle material that resists compression but not tension, with a limit stress value under compression of approximately 193.7 ± 30.6 MPa[ 17 ] and a tensile strength of 31.6 ± 16.3 MPa. According to the results of this study, in the critical areas of dental tissue, such as the cusp and neck, the maximum stress does not exceed the maximum compressive stress and tensile stress of dentin, and the occlusal veneer does not exceed its maximum flexural strength. The maximum equivalent stress indicates that after occlusal veneer restoration, the occlusal veneer bears most of the loading force, and only a small amount of force is transmitted to the tooth structure. The high load of the restoration can bear more stress within the ceramic material before fracture, reducing the force on the abutment tooth and protecting it. Restoration materials with mechanical properties similar to those of teeth can increase the lifespan of dental restoration composites, ultimately achieving the maximum preservation of healthy tooth structures[ 18 ]. Therefore, from the perspective of tooth protection, all group designs can meet the need for tooth protection. However, the von Mises stress at the highest and edge positions of the adhesive in Group C is greater than the common shear strength of adhesives, increasing the risk of edge adhesive failure. Although most positions are still safe, once adhesive failure occurs at the edges, it can easily lead to secondary caries or edge staining and even complete adhesive failure. Therefore, there are limitations in the edge design of Group C. For patients with simple early occult caries, due to the shallow cracks and sufficient enamel thickness, a 0.5 mm occlusal veneer can effectively concentrate stress on the restoration and the shallow layer of enamel or effectively slow the continued development of occult caries, thus protecting the occult teeth and reducing the risk of pulp complications. When dealing with causes such as erosion, developmental abnormalities, or wear caused by malocclusion, 1.0 mm is an ideal choice when conditions permitting minimally invasive treatment. The results of this experiment indicate that there is no significant difference in the overall trend of stress concentration and distribution in the stress distribution cloud image of the three edge design forms, which are all concentrated near the occlusal contact point. However, when observing the dental preparation surface, there are differences in the stress distribution. Group A showed a tendency toward stress concentration below the functional cusp and at the edge, while Group B showed a uniform distribution of stress on the occlusal preparation surface. In Group C, the distance between the edge and the occlusal contact point is relatively close, resulting in a closer location of stress concentration in the restoration, tooth structure, and adhesive layer, which increases the risk of failure. However, there was no significant difference in stress near the nonfunctional cusp or the occlusal contact area between the two groups. Excluding Group C1, where the occlusal veneer produced the highest von Mises stress concentration due to the proximity of the margin to the occlusal contact point, the maximum von Mises stress in the remaining groups was limited to the restoration body below the contact area. The stress reaching the preparation margin significantly decreased, and the stress transmitted to the tooth structure further decreased. In past traditional mechanical studies, Clausen et al. investigated the influence of restoration materials and preparation design on the survival probability of occlusal veneers, with thickness and material elastic modulus having a more significant impact[ 19 ]. Mores et al. reported that in anatomic crown restorations, compressive stress is concentrated at the lower occlusal contact point, and tensile stress is concentrated on the inner surface directly below the occlusal contact point. The region of tensile stress concentration corresponded to the initial location of crown fracture[ 20 ]. Cracks in occlusal veneers often originate from areas where occlusal stress is concentrated, such as the occlusal contact point or the edges of the restoration[ 15 ]. Considering the numerical difference between the von Mises stress concentration at the edge position and the maximum stress value, the edge position is not considered a high-risk area for failure compared to the occlusal contact point. However, repeated application of occlusal forces over a long period can lead to material fatigue. Once the occlusal contact area fails, the experiment is stopped, making it impossible to effectively study the mechanical characteristics of the occlusal veneer edge design. The stress distribution of the adhesive is primarily concentrated either below the occlusal contact point or at the edge area. The maximum stress of both groups A and B is less than the common shear strength of Variolink II (29 ± 3 MPa) and RelyX ARC (26 ± 5 MPa)[ 21 ]. However, the von Mises stress of the adhesive in Group C at both the highest and edge positions is greater than the common shear strength of the adhesives, indicating a greater risk of fracture. The maximum von Mises stress at the edge of the adhesive is less than the most concentrated von Mises stress at the edge below the occlusal contact point. The von Mises stress at the edge of Group B is relatively lower than the maximum von Mises stress in the adhesive layer, while the von Mises stress at the edges of Groups A and C is close to the maximum von Mises stress in the adhesive layer. Therefore, the shallow concave edges of Group B have better performance in reducing the risk of adhesive fracture. Under the experimental conditions, there are still some aspects that cannot be fully replicated. During the three-dimensional finite element modeling process, all materials are assumed to be homogeneous and isotropic, which is not realistic for dental tissues. In particular, the structurally complex dental tissue of dentin cannot be completely and realistically simulated due to technical limitations. Factors such as oral temperature, food, resin polymerization shrinkage, and fatigue have not been simulated due to experimental constraints. Conclusion 1. Under the experimental conditions, the mechanical properties of the maximum von Mises stress in the occlusal veneers of butt-jointed edges, shallow concave edges, and straight bevel edges can all meet clinical needs. Combined with the minimally invasive concept of tooth preservation, the optimal thickness of glass-ceramic occlusal veneers for maxillary first molars is 1.0 mm. 2. The maximum von Mises stress in the residual tooth tissue was greatest at the crest of the palatal alveolar ridge in all groups, which can help protect and reduce stress concentration on the abutment tooth. The adhesive stress in the straight bevel edge group is too concentrated at the adhesive edge, which can easily lead to complications. The butt-jointed edge and shallow concave edge groups have advantages in reducing tensile stress in the residual tooth tissue. Compared with the other two groups, the shallow concave edge group had certain advantages in terms of protecting the residual tooth tissue and reducing the stress concentration at the adhesive edge. Abbreviations Edge preparation method straight-beveled finishing line（SFL) chamfer finishing line(CFL) standard cuspal inclination（SCI） Declarations Ethics approval and consent to participate All experimental protocols were approved by Guiyang Stomatological Hospital Medical Ethics Committee. Informed consent was obtained from all subjects. Reference number :GYSKLL-KY-20240226-02 Consent for publication NOT APPLICABLE Availability of data and materials The datasets used and analyzed during the current study are available from the corresponding author upon reasonable request. Competing interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Acknowledgments None. Funding None. Author Contributions Q.C:Conceptualization,Data curation,Writing- Original draft preparation, Experimental operation,Reviewing,Editing,Methodology, Modeling & Simulation and Software. S.L:Reviewing,Editing, Methodology, Methodology, Modeling & Simulation and Software. Q.D , Y.W, Z.C , Y.L , M.M , Y.L :Conceptualization,Methodology,Supervision. N.X:Experimental site,Experimental operation. References Pihlstrom BL, Michalowicz BS, Johnson NW. Periodontal diseases. Lancet. 2005;366(9499):1809–20. Seo DG, Yi YA, Shin SJ, Park JW. Analysis of factors associated with cracked teeth. J Endod. 2012;38(3):288–92. Al-Akhali M, Kern M, Elsayed A, Samran A, Chaar MS. Influence of thermomechanical fatigue on the fracture strength of CAD-CAM-fabricated occlusal veneers. 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Cite Share Download PDF Status: Published Journal Publication published 06 Nov, 2024 Read the published version in BMC Oral Health → Version 1 posted Editorial decision: Revision requested 29 Jul, 2024 Reviews received at journal 28 Jul, 2024 Reviews received at journal 27 Jul, 2024 Reviewers agreed at journal 24 Jul, 2024 Reviewers agreed at journal 24 Jul, 2024 Reviews received at journal 23 Jul, 2024 Reviewers agreed at journal 18 Jul, 2024 Reviews received at journal 15 Jul, 2024 Reviewers agreed at journal 13 Jul, 2024 Reviewers agreed at journal 03 Jul, 2024 Reviewers agreed at journal 08 Apr, 2024 Reviewers invited by journal 04 Apr, 2024 Editor assigned by journal 04 Apr, 2024 Editor invited by journal 26 Mar, 2024 Submission checks completed at journal 26 Mar, 2024 First submitted to journal 16 Mar, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4112384","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":284054355,"identity":"a89cc076-3609-4426-901a-843caf4e5932","order_by":0,"name":"Qing Chen","email":"","orcid":"","institution":"Department of Prosthodontics, School of Stomatology, Guizhou Medical University,","correspondingAuthor":false,"prefix":"","firstName":"Qing","middleName":"","lastName":"Chen","suffix":""},{"id":284054356,"identity":"b5bf9ce9-9c1d-4710-b495-1b1de1c8a747","order_by":1,"name":"Siyang Luo","email":"","orcid":"","institution":"Guiyang Stomatological Hospital","correspondingAuthor":false,"prefix":"","firstName":"Siyang","middleName":"","lastName":"Luo","suffix":""},{"id":284054357,"identity":"d26ce4cf-5679-4ca5-85c0-921d09714485","order_by":2,"name":"Yujuan Wang","email":"","orcid":"","institution":"Guiyang Stomatological Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yujuan","middleName":"","lastName":"Wang","suffix":""},{"id":284054360,"identity":"d759f1dd-7d57-4bda-9531-14ba8034fed4","order_by":3,"name":"Zhu Chen","email":"","orcid":"","institution":"Guiyang Stomatological Hospital","correspondingAuthor":false,"prefix":"","firstName":"Zhu","middleName":"","lastName":"Chen","suffix":""},{"id":284054361,"identity":"b4c72f56-f8e8-4fa0-a07f-800caa751a44","order_by":4,"name":"Ying Li","email":"","orcid":"","institution":"Guizhou Medical University, Affiliated Stomatology Hospital of Guizhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Ying","middleName":"","lastName":"Li","suffix":""},{"id":284054362,"identity":"3c13d91c-1879-40fb-8153-9ba525d57c91","order_by":5,"name":"Maohua Meng","email":"","orcid":"","institution":"Guizhou Medical University, Affiliated Stomatology Hospital of Guizhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Maohua","middleName":"","lastName":"Meng","suffix":""},{"id":284054363,"identity":"5b829271-b4d0-48af-84c9-80a4073a6b66","order_by":6,"name":"Yamei Li","email":"","orcid":"","institution":"Guiyang Stomatological Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yamei","middleName":"","lastName":"Li","suffix":""},{"id":284054364,"identity":"9e8ff504-7785-4d74-8ee8-ccc9924ba1ba","order_by":7,"name":"Nan Xiao","email":"","orcid":"","institution":"Jingde Dental Clinic","correspondingAuthor":false,"prefix":"","firstName":"Nan","middleName":"","lastName":"Xiao","suffix":""},{"id":284054365,"identity":"16d609a5-3759-4529-a896-d8d0a40b0dbf","order_by":8,"name":"Qiang Dong","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA8klEQVRIiWNgGAWjYDCCA8icD0DMx8DATISWBAibcQYDgwQbSVqYeYjRwne89/DLnz/uyZnzrzGTtqk4XMfG3nzYgKHGJhqXFskz59KseRKKjS1nvDGTzjlzWIKN51hyAsOxtNwGHFoMbuSYGTMkJCRuuHEs2Ti3DahFIsf4AGPDYbxaDH/AtFgSqcX4AQ9Iy/nmg48ZoVoS8GmRPHPGjJknLcHY4AbzwYc9Z9Il24B+MUjA4xe+4z3GH3/YJMgZnD/YcOBHhTU/PzDEJD7U2ODUAgRsEmBKIgFJLAGbQgRg/gCm+A/gVzYKRsEoGAUjFwAAYBtbAlED4pEAAAAASUVORK5CYII=","orcid":"","institution":"Guizhou Medical University, Affiliated Stomatology Hospital of Guizhou Medical University","correspondingAuthor":true,"prefix":"","firstName":"Qiang","middleName":"","lastName":"Dong","suffix":""}],"badges":[],"createdAt":"2024-03-16 09:32:21","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4112384/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4112384/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12903-024-05121-9","type":"published","date":"2024-11-06T15:57:50+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":53758027,"identity":"72eb5e28-42f5-486e-ba42-ec9bcd307386","added_by":"auto","created_at":"2024-03-29 19:11:32","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":228341,"visible":true,"origin":"","legend":"\u003cp\u003eModel of maxillary first molar with the same morphology as the isolated tooth. Models prepared for each group\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-4112384/v1/5ac5397b59dd4e6d16e4352a.png"},{"id":53758868,"identity":"f490bdf5-e30b-4167-b4d0-022fd59a5de8","added_by":"auto","created_at":"2024-03-29 19:19:32","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":119644,"visible":true,"origin":"","legend":"\u003cp\u003e3D solid model of abutment teeth and occlusal veneer after GEOMAGIC 2017 processing.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-4112384/v1/80d68c856fc394272f27ecc0.png"},{"id":53758028,"identity":"4ac4952f-f0be-40ff-b4cf-710454f228d9","added_by":"auto","created_at":"2024-03-29 19:11:32","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":230220,"visible":true,"origin":"","legend":"\u003cp\u003eFinite element model\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-4112384/v1/6171167586bbef09a1f12db3.png"},{"id":53758025,"identity":"a3bbede1-8b6b-4445-9505-0b18e04bb9e9","added_by":"auto","created_at":"2024-03-29 19:11:32","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":61865,"visible":true,"origin":"","legend":"\u003cp\u003eMaximum von Mises stress at the edge of each component in each group. Maximum von Mises stress in different parts of the groups\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-4112384/v1/02d2c02ed2c8bc566410659d.png"},{"id":53758869,"identity":"a42b6000-c532-431d-ada1-619edb217a18","added_by":"auto","created_at":"2024-03-29 19:19:32","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":1991893,"visible":true,"origin":"","legend":"\u003cp\u003eStress distribution in the occlusal veneer for each group. Stress distribution in the occlusal veneer for each group. Distribution of stresses in the teeth of each group. Stress distribution at the edge of the occlusal veneer in each group. Stress distribution at the edge of the tooth preparation in each group. Adhesive edge stress distribution.\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-4112384/v1/a43684884e8f37eb2efeab2c.png"},{"id":68750431,"identity":"560d517d-1383-47e7-accf-989f91d2fc37","added_by":"auto","created_at":"2024-11-11 16:12:00","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":4719425,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4112384/v1/77e73635-54ec-47bc-b80d-1cf8ec544d82.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Three-dimensional finite element analysis of occlusal stress on maxillary first molars with different marginal morphologies restored with occlusal veneers","fulltext":[{"header":"Highlights","content":"\u003cul\u003e\n \u003cli\u003eThis experiment combined finite element analysis with traditional mechanical experiments and prepared models with identical shapes using 3D printing. This approach avoided experimental errors caused by variations in the shape of the natural teeth among individuals, uneven bonding agent thickness, and different design morphologies of the occlusal surface. Additionally, the roughness of the prepared surface more closely resembled the true roughness encountered in clinical settings.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eBy incorporating periodontal ligament hyperelastic materials into jaw dentition, a more realistic nonlinear analysis of periodontal ligament deformation was conducted. By applying biting forces and simulating the movement of biting, dynamic contact results were obtained that differed from the static loading stresses typically used in finite element analyses.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eDaily chewing is not simply a collision between highly elastic model materials and restorations or teeth, as in extraoral experiments, but rather simulates chewing by using materials that are closer to the mechanical properties of the daily foods of primates.\u003c/li\u003e\n\u003c/ul\u003e"},{"header":"Background","content":"\u003cp\u003eIn clinical dentistry, various degrees of tooth tissue defects are often caused by decay, attrition, erosion and occult cracks. The incidence of occult cracked teeth is increasing every year. This is one of the reasons for the loss of permanent molars after decay and periodontal disease[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. The first molar is the tooth position with the highest incidence of occult cracked teeth[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAs a relatively newer form of fixed prosthodontics, occlusal veneer has the distinct advantage of removing fewer tooth structures compared to full-coverage crowns while ensuring effective bonding retention and resistance. It can preserve the maximum amount of healthy tooth tissue. In terms of its load-bearing capacity, a 0.5\u0026ndash;1.5 mm occlusal veneer may be an effective alternative to traditional crown restoration under normal anticipated occlusal forces in the mouth[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. The selection of occlusal veneer materials needs to take into account both fracture resistance and bonding performance, so glass-based ceramics[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e] and resin-based ceramics[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] are commonly used. With the rapid development of chairside CAD/CAM, glass ceramics are becoming increasingly widely used in clinical practice[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eDue to the thin material used for occlusal veneer restoration for posterior teeth, which relies entirely on bonding retention, some common clinical complications, including restoration fracture, restoration detachment, and complications affecting periodontal and dental pulp tissue, are common. Currently, clinical reports on occlusal veneer primarily focus on medium-term and short-term observations and case reports, while long-term clinical studies exceeding 10 years are rare. There is significant controversy in both domestic and foreign reports on the thickness of occlusal veneers, with no unanimous consensus. The commonly used preparation methods reported in the literature for clinical applications currently include straight-beveled finishing lines (SFL), chamfer finishing lines (CFL), and standard cuspal inclinations (SCI)[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Among domestic and foreign research results, 分歧 shows that margin design can achieve the best long-term success rate, and further research is needed.\u003c/p\u003e \u003cp\u003eThis study aimed to explore the optimal design of occlusal veneer margins for maxillary first permanent molars by combining finite element analysis, secondary digital modeling, and traditional mechanical experiments on tooth preparation. By analyzing the stress distribution of different thicknesses and margin preparation shapes under different conditions, this study provides mechanical research evidence and a reference for the exploration and research of the best design plan for occlusal veneer margins of maxillary first permanent molars.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eA maxillary first molar with an intact crown, no caries damage, and no occult cracks was extracted due to periodontitis. The tooth stones and periodontal tissue were removed with informed consent from the patient. The 3Shape intraoral scanner was used to obtain 3D images. The STL data were exported, and GEOMAGIC 2017 was used to process the polygonization and surface smoothing to obtain a three-dimensional solid model of the maxillary first molar.\u003c/p\u003e \u003cp\u003eThe three-dimensional solid model was imported into a photopolymerization 3D printer for printing. After trimming the casting channels, 18 maxillary first molar models with morphologies identical to those of the extracted teeth were obtained.\u003c/p\u003e \u003cp\u003eExperiment Grouping: According to the different groups, dental preparation was performed based on tooth morphology (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), and the models were divided into three groups, as shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eExperimental groups\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEdge preparation method\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eocclusal veneer Preparation thickness\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003estraight-beveled finishing line(SFL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.5 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003echamfer finishing line(CFL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.5 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003estandard cuspal inclination(SCI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.5 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eUsing the same experienced surgeon, the same preparation was performed on the different edge morphologies in groups A, B, and C. Grinding and polishing were then applied to round off all points, lines, and angles. Six teeth were prepared for each group. An accuracy of 0.01 mm was used for the thickness measurement scale, and eight fixed measurement points were designed to evaluate the prepared teeth. This was done to ensure that the tooth preparation met the design requirements for each group.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eModel of maxillary first molar with the same morphology as the isolated tooth. Models prepared for each group\u003c/p\u003e \u003cp\u003eAfter scanning the prepared model after screening with 3Shape, occlusal veneers with different marginal shapes but the same occlusion shape were designed in 3Shape software. Then, the STL files were exported and repaired using Geomagic 2017. After smoothing, polygonization, and surface modeling, the processed three-dimensional solid model of the prepared posterior tooth and the processed three-dimensional solid model of the occlusal veneer were obtained (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Three sets of occlusal veneer and prepared tooth STL data were exported to SolidWorks software. The corresponding groups of teeth and occlusal veneers were assembled, and Boolean operations were performed to eliminate scanning errors. Additionally, a 100-micron adhesive layer was created by outwardly expanding the tooth preparation surface contour. Using the surface deformation feature, nine sets of experimental models were created with thicknesses of 0.5 mm and 1.0 mm while maintaining the same occlusal surface morphology (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Additionally, we established periodontal tissue solid models, such as periodontal ligaments, cortical bone, and cancellous bone, through reverse engineering of CBCT data for assembly (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eEach experimental model was imported into the finite element analysis software Abaqus 2021. Grid division was performed, boundary constraints were set, and material parameters for different structural components were input(Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The number of elements and nodes for each model was obtained.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e3D solid model of abutment teeth and occlusal veneer after GEOMAGIC 2017 processing.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eFinite element model\u003c/h2\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAfter the deformation of the surface, the edge preparation methods were divided into 9 experimental groups.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003egroups\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eEdge preparation method\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eocclusal veneer Preparation thickness\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eA1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003estraight-beveled finishing line\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.5 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eA2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003estraight-beveled finishing line\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.0 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eA3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003estraight-beveled finishing line\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.5 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eB1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003echamfer finishing line\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.5 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eB2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003echamfer finishing line\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.0 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eB3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003echamfer finishing line\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.5 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003estandard cuspal inclination\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.5 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003estandard cuspal inclination\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.0 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003estandard cuspal inclination\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.5 mm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eVarious material accessories parameters\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMaterial attributes\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003emodulus of elasticity/MPa\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePoisson's ratio\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eenamel [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e84100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.30\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003edentine [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.31\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eadhesives[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.28\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePeriodontal ligament[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.45\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCortical bone[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13700\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.30\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCancellous bone[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e345\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.31\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLithium disilicate ceramics\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e95000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.19\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBite[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.47\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eConstraint conditions are added to set the freedom degree of the tooth root section to 0 (i.e., displacements and rotations in the X, Y, and Z directions are all constrained to 0). A simulated maximum biting force of 800 was applied to the mandible, which is the force borne by the teeth.[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eTo separate the tooth model from the jawbone model, the obstruction of the jawbone was removed, and the peak stress results of each group and component under the same biting force loading were observed according to three thicknesses (0.5 mm, 1.0 mm, 1.5 mm) and three edge design forms (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e,Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). For Groups A and B of occlusal veneers, as the thickness of the occlusal veneer increases, the maximum von Mises stress also increases. Group B exhibited relatively smaller changes, but Group C showed the opposite trend. Group C1 had the highest von Mises stress, and as the thickness of the occlusal veneer increased, the stress decreased.\u003c/p\u003e \u003cp\u003eFor the remaining tooth structure, as the thickness of the occlusal veneer continues to increase, the maximum von Mises stress of the remaining tooth structure gradually increases.\u003c/p\u003e \u003cp\u003eThe trend of all groups in the adhesive layer was the same, gradually decreasing as the thickness of the occlusal veneer increased. Group C was significantly larger than Groups A and B.\u003c/p\u003e \u003cp\u003eThe results of finding the peak stress values at the edges of each model part in each group were as follows: The stress was concentrated at the edges of the parts immediately below the palatal cusp, which is the functional cusp, in all groups. The maximum von Mises stress at the occlusal veneer edges was far lower than that at the occlusal contact points. With increasing occlusal veneer thickness, the von Mises stress gradually decreased for all the parts and groups. The stress at the edges of all the components in Group C was significantly greater than that in Groups A and B. The maximum von Mises stress at the occlusal veneer edges was far lower than that at the occlusal contact points. As the thickness of the occlusal veneer increased, the von Mises stress gradually decreased.\u003c/p\u003e \u003cp\u003eThe maximum von Mises stress at the edges of the adhesive was lower than the most concentrated position of von Mises stress below the occlusal contact points. Compared to those in the adhesive layer, the edges in Group B had relatively lower von Mises stress, while the edges in Groups A and C were close to the maximum von Mises stress of the adhesive layer. As the thickness of the occlusal veneer increased, the von Mises stress gradually decreased (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eMaximum von Mises stress at the edge of each component in each group. Maximum von Mises stress in different parts of the groups\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMaximum von Mises stresses and stress at the edge for each component in each group.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGroups\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOcclusal veneer\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDentin\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eDonding layer\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eOcclusal veneer edges\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eDental preparation margins\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eEdge of adhesive layer\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eA1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e181.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e20.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e14.71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e24.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e9.94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e14.71\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eA2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e194.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e20.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e13.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e22.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e9.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e13.37\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eA3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e219.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e21.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e19.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e8.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e11.86\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e156.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e26.56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e11.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e17.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e9.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e9.73\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e159.93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e26.57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e16.84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e8.82\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e8.41\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e169.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e26.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e9.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e14.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e8.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e7.76\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e234.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e28.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e28.76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e46.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e26.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e25.11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e181.53\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e32.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e27.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e44.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e24.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e24.02\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eStress distribution in the occlusal veneer for each group. Stress distribution in the occlusal veneer for each group. Distribution of stresses in the teeth of each group. Stress distribution at the edge of the occlusal veneer in each group. Stress distribution at the edge of the tooth preparation in each group. Adhesive edge stress distribution.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eCommon complications in occlusal veneer clinical treatment include prosthesis fracture, prosthesis detachment, dentin hypersensitivity and pulp complications, poor marginal sealing, marginal staining and secondary caries. Among them, prosthesis fracture is the primary cause of occlusal veneer failure, which is directly caused by the concentration of occlusal stress[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Cracks often originate from sites where occlusal stress is concentrated at occlusal contact points or at the edges of the prosthesis[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. The reason for the detachment of the prosthesis is bonding failure. When the occlusal force is concentrated on the bonding interface for a long time, the bonding material will be fatigued, which will cause the bonding agent to break. However, at present, the mechanical analysis of occlusal veneers mainly relies on traditional methods such as analog impact machines or finite element analysis of static stress loading. Therefore, to avoid complications and prolong the lifespan and survival rate of prostheses, more experimental methods that more closely mimic real preparation and stress conditions are needed.\u003c/p\u003e \u003cp\u003eThe selection of occlusal materials is not simply a collision between highly elastic model materials and prostheses or teeth, as in extracorporeal experiments, but rather involves various food items with different elastic moduli serving as the medium for force transmission during daily chewing. Reference studies on the mechanical properties of primate foods can provide insights into this process[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. A 2 mm-thick plate was placed between the first molars on the right side of the upper jaw. The small plate thickness was selected to ensure optimal adaptation of the deformed plate to the occlusal surface of the molars under biting force. The Young's modulus of the plate was set to 20 MPa, which corresponds to the elastic modulus of the almond under compression, and the Poisson's ratio was 0.47. Such occlusal materials have broader representative significance. In this experiment, the experimental model was assembled into a jawbone model for stress loading, and the finite element analysis results of dynamic contact were obtained.\u003c/p\u003e \u003cp\u003eIn terms of the final restoration strength, the experimental results of this study confirm the feasibility of minimally invasive treatment with posterior occlusal veneers. Clinically, the normal biting force in the premolar region of the upper jaw is between 222\u0026ndash;445 N. During biting, the biting force is approximately 800 N[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. The maximum flexural strength of lithium disilicate glass-ceramics reaches 360 MPa[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. The average flexural strength values of the occlusal veneer of the maxillary first molars in each group were all lower than the abovementioned values. Dental tissue is a brittle material that resists compression but not tension, with a limit stress value under compression of approximately 193.7\u0026thinsp;\u0026plusmn;\u0026thinsp;30.6 MPa[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] and a tensile strength of 31.6\u0026thinsp;\u0026plusmn;\u0026thinsp;16.3 MPa. According to the results of this study, in the critical areas of dental tissue, such as the cusp and neck, the maximum stress does not exceed the maximum compressive stress and tensile stress of dentin, and the occlusal veneer does not exceed its maximum flexural strength. The maximum equivalent stress indicates that after occlusal veneer restoration, the occlusal veneer bears most of the loading force, and only a small amount of force is transmitted to the tooth structure. The high load of the restoration can bear more stress within the ceramic material before fracture, reducing the force on the abutment tooth and protecting it. Restoration materials with mechanical properties similar to those of teeth can increase the lifespan of dental restoration composites, ultimately achieving the maximum preservation of healthy tooth structures[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Therefore, from the perspective of tooth protection, all group designs can meet the need for tooth protection. However, the von Mises stress at the highest and edge positions of the adhesive in Group C is greater than the common shear strength of adhesives, increasing the risk of edge adhesive failure. Although most positions are still safe, once adhesive failure occurs at the edges, it can easily lead to secondary caries or edge staining and even complete adhesive failure. Therefore, there are limitations in the edge design of Group C.\u003c/p\u003e \u003cp\u003eFor patients with simple early occult caries, due to the shallow cracks and sufficient enamel thickness, a 0.5 mm occlusal veneer can effectively concentrate stress on the restoration and the shallow layer of enamel or effectively slow the continued development of occult caries, thus protecting the occult teeth and reducing the risk of pulp complications. When dealing with causes such as erosion, developmental abnormalities, or wear caused by malocclusion, 1.0 mm is an ideal choice when conditions permitting minimally invasive treatment.\u003c/p\u003e \u003cp\u003eThe results of this experiment indicate that there is no significant difference in the overall trend of stress concentration and distribution in the stress distribution cloud image of the three edge design forms, which are all concentrated near the occlusal contact point. However, when observing the dental preparation surface, there are differences in the stress distribution. Group A showed a tendency toward stress concentration below the functional cusp and at the edge, while Group B showed a uniform distribution of stress on the occlusal preparation surface. In Group C, the distance between the edge and the occlusal contact point is relatively close, resulting in a closer location of stress concentration in the restoration, tooth structure, and adhesive layer, which increases the risk of failure. However, there was no significant difference in stress near the nonfunctional cusp or the occlusal contact area between the two groups. Excluding Group C1, where the occlusal veneer produced the highest von Mises stress concentration due to the proximity of the margin to the occlusal contact point, the maximum von Mises stress in the remaining groups was limited to the restoration body below the contact area. The stress reaching the preparation margin significantly decreased, and the stress transmitted to the tooth structure further decreased.\u003c/p\u003e \u003cp\u003eIn past traditional mechanical studies, Clausen et al. investigated the influence of restoration materials and preparation design on the survival probability of occlusal veneers, with thickness and material elastic modulus having a more significant impact[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. Mores et al. reported that in anatomic crown restorations, compressive stress is concentrated at the lower occlusal contact point, and tensile stress is concentrated on the inner surface directly below the occlusal contact point. The region of tensile stress concentration corresponded to the initial location of crown fracture[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Cracks in occlusal veneers often originate from areas where occlusal stress is concentrated, such as the occlusal contact point or the edges of the restoration[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Considering the numerical difference between the von Mises stress concentration at the edge position and the maximum stress value, the edge position is not considered a high-risk area for failure compared to the occlusal contact point. However, repeated application of occlusal forces over a long period can lead to material fatigue. Once the occlusal contact area fails, the experiment is stopped, making it impossible to effectively study the mechanical characteristics of the occlusal veneer edge design.\u003c/p\u003e \u003cp\u003eThe stress distribution of the adhesive is primarily concentrated either below the occlusal contact point or at the edge area. The maximum stress of both groups A and B is less than the common shear strength of Variolink II (29\u0026thinsp;\u0026plusmn;\u0026thinsp;3 MPa) and RelyX ARC (26\u0026thinsp;\u0026plusmn;\u0026thinsp;5 MPa)[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. However, the von Mises stress of the adhesive in Group C at both the highest and edge positions is greater than the common shear strength of the adhesives, indicating a greater risk of fracture.\u003c/p\u003e \u003cp\u003eThe maximum von Mises stress at the edge of the adhesive is less than the most concentrated von Mises stress at the edge below the occlusal contact point. The von Mises stress at the edge of Group B is relatively lower than the maximum von Mises stress in the adhesive layer, while the von Mises stress at the edges of Groups A and C is close to the maximum von Mises stress in the adhesive layer. Therefore, the shallow concave edges of Group B have better performance in reducing the risk of adhesive fracture.\u003c/p\u003e \u003cp\u003eUnder the experimental conditions, there are still some aspects that cannot be fully replicated. During the three-dimensional finite element modeling process, all materials are assumed to be homogeneous and isotropic, which is not realistic for dental tissues. In particular, the structurally complex dental tissue of dentin cannot be completely and realistically simulated due to technical limitations. Factors such as oral temperature, food, resin polymerization shrinkage, and fatigue have not been simulated due to experimental constraints.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003e1.\u0026nbsp;Under the experimental conditions, the mechanical properties of the maximum von Mises stress in the occlusal veneers of butt-jointed edges, shallow concave edges, and straight bevel edges can all meet clinical needs.\u0026nbsp;Combined with\u0026nbsp;the minimally invasive concept of tooth preservation, the optimal thickness of glass-ceramic occlusal veneers for maxillary first molars is 1.0 mm.\u003c/p\u003e\n\u003cp\u003e2. The maximum von Mises stress in the residual tooth tissue was greatest at the crest of the palatal alveolar ridge in all groups, which can help protect and reduce stress concentration on the abutment tooth. The adhesive stress in the straight bevel edge group is too concentrated at the adhesive edge, which can easily lead to complications. The butt-jointed edge and shallow concave edge groups have advantages in reducing tensile stress in the residual tooth tissue. Compared with the other two groups, the shallow concave edge group had certain advantages in terms of protecting the residual tooth tissue and reducing the stress concentration at the adhesive edge.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv align=\"\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"513\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"100%\"\u003e\n \u003cp\u003eEdge preparation method\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"100%\"\u003e\n \u003cp\u003estraight-beveled finishing line（SFL)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"100%\"\u003e\n \u003cp\u003echamfer finishing line(CFL)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"100%\"\u003e\n \u003cp\u003estandard cuspal inclination（SCI）\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e"},{"header":"Declarations","content":"\u003ch2\u003eEthics approval and consent to participate\u003c/h2\u003e\n\u003cp\u003e\u0026nbsp;All experimental protocols were approved by Guiyang Stomatological Hospital Medical Ethics Committee.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Informed consent was obtained from all subjects.\u003c/p\u003e\n\u003cp\u003eReference number :GYSKLL-KY-20240226-02\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eConsent for publication\u003c/h2\u003e\n\u003cp\u003eNOT APPLICABLE\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eAvailability of data and materials\u003c/h2\u003e\n\u003cp\u003eThe datasets used and analyzed during the current study are available from the corresponding author\u0026nbsp;upon\u0026nbsp;reasonable request.\u003c/p\u003e\n\u003ch2\u003eCompeting interests\u003c/h2\u003e\n\u003cp\u003eThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eAcknowledgments\u003c/h2\u003e\n\u003cp\u003eNone.\u003c/p\u003e\n\u003ch2\u003eFunding\u003c/h2\u003e\n\u003cp\u003eNone.\u003c/p\u003e\n\u003ch2\u003eAuthor Contributions\u003c/h2\u003e\n\u003cp\u003eQ.C:Conceptualization,Data curation,Writing- Original draft preparation,\u0026nbsp;Experimental operation,Reviewing,Editing,Methodology, Modeling \u0026amp; Simulation\u0026nbsp;and\u0026nbsp;Software.\u003c/p\u003e\n\u003cp\u003eS.L:Reviewing,Editing,\u0026nbsp;Methodology, Methodology, Modeling \u0026amp; Simulation\u0026nbsp;and\u0026nbsp;Software.\u003c/p\u003e\n\u003cp\u003eQ.D , Y.W, Z.C , Y.L , M.M , Y.L :Conceptualization,Methodology,Supervision.\u003c/p\u003e\n\u003cp\u003eN.X:Experimental site,Experimental operation.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003ePihlstrom BL, Michalowicz BS, Johnson NW. Periodontal diseases. Lancet. 2005;366(9499):1809\u0026ndash;20.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSeo DG, Yi YA, Shin SJ, Park JW. Analysis of factors associated with cracked teeth. J Endod. 2012;38(3):288\u0026ndash;92.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAl-Akhali M, Kern M, Elsayed A, Samran A, Chaar MS. Influence of thermomechanical fatigue on the fracture strength of CAD-CAM-fabricated occlusal veneers. J Prosthet Dent. 2019;121(4):644\u0026ndash;50.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAndrade JP, Stona D, Bittencourt HR, Borges GA, Burnett LHJ, Spohr AM. Effect of Different Computer-aided Design/Computer-aided Manufacturing (CAD/CAM) Materials and Thicknesses on the Fracture Resistance of Occlusal Veneers. Oper Dent. 2018;43(5):539\u0026ndash;48.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEdelhoff D, Guth JF, Erdelt K, Brix O, Liebermann A. Clinical performance of occlusal onlays made of lithium disilicate ceramic in patients with severe tooth wear up to 11 years. Dent Mater. 2019;35(9):1319\u0026ndash;30.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOudkerk J, Eldafrawy M, Bekaert S, Grenade C, Vanheusden A, Mainjot A. The one-step no-prep approach for full-mouth rehabilitation of worn dentition using PICN CAD-CAM restorations: 2-yr results of a prospective clinical study. J Dent. 2020;92:103245.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKrummel A, Garling A, Sasse M, Kern M. Influence of bonding surface and bonding methods on the fracture resistance and survival rate of full-coverage occlusal veneers made from lithium disilicate ceramic after cyclic loading. Dent Mater. 2019;35(10):1351\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVeneziani M. Posterior indirect adhesive restorations: updated indications and the Morphology Driven Preparation Technique. Int J Esthet Dent. 2017;12(2):204\u0026ndash;30.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDejak B, Mlotkowski A. A comparison of stresses in molar teeth restored with inlays and direct restorations, including polymerization shrinkage of composite resin and tooth loading during mastication. Dent Mater. 2015;31(3):e77\u0026ndash;87.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNakamura T, Wakabayashi K, Kinuta S, Nishida H, Miyamae M, Yatani H. Mechanical properties of new self-adhesive resin-based cement. J Prosthodont Res. 2010;54(2):59\u0026ndash;64.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCelebi AT, Icer E, Eren MM, Baykasoglu C, Mugan A, Yildiz E. Thermal-stress analysis of ceramic laminate veneer restorations with different incisal preparations using microcomputed tomography-based 3D finite element models. J Mech Behav Biomed Mater. 2017;75:302\u0026ndash;13.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWilliams SH, Wright BW, Truong V, Daubert CR, Vinyard CJ. Mechanical properties of foods used in experimental studies of primate masticatory function. Am J Primatol. 2005;67(3):329\u0026ndash;46.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHeintze SD, Monreal D, Reinhardt M, Eser A, Peschke A, Reinshagen J, Rousson V. Fatigue resistance of all-ceramic fixed partial dentures - Fatigue tests and finite element analysis. Dent Mater. 2018;34(3):494\u0026ndash;507.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMorimoto S, Rebello de Sampaio FB, Braga MM, Sesma N, Ozcan M. Survival Rate of Resin and Ceramic Inlays, Onlays, and Overlays: A Systematic Review and Meta-analysis. J Dent Res. 2016;95(9):985\u0026ndash;94.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRocca GT, Saratti CM, Cattani-Lorente M, Feilzer AJ, Scherrer S, Krejci I. The effect of a fiber reinforced cavity configuration on load bearing capacity and failure mode of endodontically treated molars restored with CAD/CAM resin composite overlay restorations. J Dent. 2015;43(9):1106\u0026ndash;15.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNiem T, Youssef N, Wostmann B. Energy dissipation capacities of CAD-CAM restorative materials: A comparative evaluation of resilience and toughness. J Prosthet Dent. 2019;121(1):101\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChun K, Choi H, Lee J. Comparison of mechanical property and role between enamel and dentin in the human teeth. J Dent Biomech. 2014;5:1758736014520809.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVianna A, Prado CJD, Bicalho AA, Pereira R, Neves FDD, Soares CJ. Effect of cavity preparation design and ceramic type on the stress distribution, strain and fracture resistance of CAD/CAM onlays in molars. J Appl Oral Sci. 2018;26:e20180004.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eClausen JO, Abou Tara M, Kern M. Dynamic fatigue and fracture resistance of nonretentive all-ceramic full-coverage molar restorations. Influence of ceramic material and preparation design. Dent Mater. 2010;26(6):533\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMores RT, Borba M, Corazza PH, Della Bona A, Benetti P. Influence of surface finishing on fracture load and failure mode of glass ceramic crowns. J Prosthet Dent. 2017;118(4):511\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGraiff L, Piovan C, Vigolo P, Mason PN. Shear bond strength between feldspathic CAD/CAM ceramic and human dentine for two adhesive cements. J Prosthodont. 2008;17(4):294\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-oral-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ohea","sideBox":"Learn more about [BMC Oral Health](http://bmcoralhealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/ohea/default.aspx","title":"BMC Oral Health","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"occlusal veneer, Maxillary first molar, Differential edges, Three-dimensional finite element, Stress","lastPublishedDoi":"10.21203/rs.3.rs-4112384/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4112384/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAs a relatively new fixed prosthesis method, there are differences in the research results at home and abroad regarding which edge design of occlusal veneers can achieve the best long-term success rate. Further research is needed. The three-dimensional finite element method was used to conduct stress analysis on occlusal veneers of maxillary first permanent molars with different thicknesses and margin preparation designs. The aim of this study was to provide mechanical research evidence and a reference for exploring standardized clinical protocols for the design of occlusal veneer restorations of maxillary first molars.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethod\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA 3Shape was used to scan the maxillary first molar teeth in vitro, after which 3D printing was performed. Three different edge designs were applied to identical model teeth: straight-beveled finishing line(SFL), chamfer finishing line(CFL), and standard cuspal inclination(SCI). Preparation was carried out with a thickness of 0.5 mm. Using the surface deformation feature, the occlusal veneer was thickened by 0.5 mm and 1.0 mm, and periodontal ligaments were added. They were then placed into the upper and lower jaws and dental arches. Finite element analysis was performed after applying bite force dispersion to the loading area on the mandible following dynamic contact.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e1. As the thickness increased, the maximum von Mises stress in the occlusal veneer increased for both the SFL and CFL, while the SCI exhibited the opposite trend.\u003c/p\u003e\n\u003cp\u003e2. The trend of the maximum von Mises stress in the adhesive layer decreases gradually with increasing thickness of the occlusal veneer. The stress of the SFL and CFL is concentrated primarily at the edge position below the functional cusp, resulting in relatively low adhesive stress. However, in the SCI group, the maximum stress at the edge of the adhesive layer exceeded the maximum shear strength of commonly used adhesives.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eUnder the experimental conditions, the mechanical properties of the maximum von Mises stress for the SFL, CFL, and SCI Occlusal veneer met clinical needs. Incorporating the minimally invasive concept of tooth preservation, a thickness of 1.0 mm is optimal for glass ceramic occlusal veneers on maxillary first molars. However.\u003c/p\u003e","manuscriptTitle":"Three-dimensional finite element analysis of occlusal stress on maxillary first molars with different marginal morphologies restored with occlusal veneers","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-03-29 19:11:28","doi":"10.21203/rs.3.rs-4112384/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-07-29T05:14:27+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-07-28T07:53:24+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-07-27T22:47:52+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"172246391349376792500147371438402553649","date":"2024-07-24T09:53:32+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"44222759206165541477082794868550829933","date":"2024-07-24T09:53:32+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-07-23T15:53:24+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"110465959484308476249351565458703073797","date":"2024-07-18T14:32:37+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-07-15T20:59:25+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"331367117382169767509263064672376269754","date":"2024-07-13T18:45:33+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"319973374175813550812851412858713933496","date":"2024-07-04T02:31:41+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"6c70ea03-467f-44bb-a3ac-29b561e5eb0b","date":"2024-04-08T07:31:36+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-04-04T19:35:14+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-04-04T19:29:04+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2024-03-26T11:28:04+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-03-26T11:23:33+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Oral Health","date":"2024-03-16T09:31:07+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-oral-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ohea","sideBox":"Learn more about [BMC Oral Health](http://bmcoralhealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/ohea/default.aspx","title":"BMC Oral Health","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"f130be29-6d8d-404e-a3dd-05b0729cdc49","owner":[],"postedDate":"March 29th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-11-11T16:07:50+00:00","versionOfRecord":{"articleIdentity":"rs-4112384","link":"https://doi.org/10.1186/s12903-024-05121-9","journal":{"identity":"bmc-oral-health","isVorOnly":false,"title":"BMC Oral Health"},"publishedOn":"2024-11-06 15:57:50","publishedOnDateReadable":"November 6th, 2024"},"versionCreatedAt":"2024-03-29 19:11:28","video":"","vorDoi":"10.1186/s12903-024-05121-9","vorDoiUrl":"https://doi.org/10.1186/s12903-024-05121-9","workflowStages":[]},"version":"v1","identity":"rs-4112384","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4112384","identity":"rs-4112384","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}